Sorry I wasn't aware that your Canadian certificate has your marriage name instead of maiden name. I thought you had your maiden name on it all along.
Since your citizenship certificate has your married name on it instead of maiden name, then you have no choice but to do a legal name change to get your maiden name on the certificate.
This is why I didn't want my spouse to have married name on PR card or Canadian citizenship. I don't want her to go through the steps you are going through. It's way too much hassle trying to revert to maiden name if needed. In my opinion, it is best for everyone to keep their maiden on their PR card / citizenship. It is an equivalent of having a Canadian birth certificate. Everyone is pretty much born with their maiden names. Just show marriage certificate or divorce papers to easily switch names on IDs (DL, Health card, passport) without resorting to any legal name change.